1. Field of the Invention
The present invention relates to a mobile network configuration and method for operating a mobile network configuration. In particular, the mobile network includes a network controller operating as a nod on a WAN and a plurality of mobile subnets with at least two communication links established between each mobile subnet and the network controller.
2. Description of the Related Art
Mobile subnets configured to establish two or more communication links with a cellular network to access a WAN are known. One such mobile subnet is disclosed in copending and commonly assigned patent application Ser. No. 11/650,634 by Fulknier et al. filed on Jan. 6, 2007, entitled MOBILE ROUTER DEVICE. As described therein, two or more mobile router devices each having a single cellular network interface device installed thereon are interconnected or stacked together and controlled by a master router. The master router directs each cellular network interface device to establish a communication channel or link with a cellular network and directs outgoing network traffic to the cellular network over any one of the communication channels. Moreover any outgoing network traffic is routed directly to its destination IP address e.g. on a WAN.
One advantage of the router stack disclosed in the '634 reference is that the master router operates to distribute network traffic exiting from the router stack over all of the available communication channels and the network traffic can be equally load balanced over the available communication channels or otherwise routed to any one of the available communication channels according to network conditions, channel conditions, and other factors.
The router stack disclosed in the '634 reference operates such that any reply traffic responsive to the network traffic exiting from the router stack is returned to the router stack over the same communication channel that it exited the router stack over. One problem with the '634 reference network configuration occurs when one or more of the communication channels is no longer available or when an IP address assigned to one or more of the communication channels is changed. As a result, reply traffic can be lost when one of the communication channels is no longer available or its IP address is changed. Another problem with the '634 reference network configuration occurs when reply traffic bandwidth is wider than channel bandwidth capacity and this can degrade the overall performance of the mobile subnet. Accordingly there is a need in the art to control the distribution of reply traffic to a mobile subnet by directing reply data traffic over any the available communication channels as demanded by instantaneous network conditions.